FORMATION OF INTERLAYER IN MULTI-MATERIAL INCONEL 718 AND TI6AL4V ALLOY PRODUCTS OBTAINED BY SELECTIVE LASER MELTING

This study examines the Inconel 718/Ti6Al4V multi-material with Cu and Cu+Nb interlayer produced by selective laser melting (SLM). To achieve this, it is important to investigate the microstructure, the chemical and phase composition, and the hardness of the interfacial zone in the multi-material samples, as well as to determine the effect of the use of interlayer on the mechanical properties of multi-material samples. It was observed that no significant defects were present in the alloy regions (Ti6Al4V and Inconel 718) of multi-materials. However, defects were identified in the Cu and Nb regions, as well as in the Cu/Nb interfacial zone. The interfacial zones of the Ti6Al4V/Nb and Inconel 718/Cu exhibited a sharp transition in the chemical composition. A comparable pattern was observed in Ti6Al4V/Cu interfacial zone, while the Nb/Cu interfacial zone exhibited a gradual transition from one element to another. The formation of island macro-segregation was observed in all interfacial zones: Ti6Al4V/Cu, Ti6Al4V/Nb, Nb/Cu and Inconel 718/Cu. No new phases were identified in the production of the multi-material samples. The multi-material samples with the Cu+Nb interlayer exhibited enhanced mechanical properties compared with samples with Cu interlayer. The tensile strength of the multi-material sample with Cu interlayer reached 790 MPa, while with the Cu+Nb interlayer reached 910 MPa. These values are relatively high, but nevertheless lie below Inconel 718 or Ti6Al4V alloy properties.